The overall objective of this four year project is to target and study clinical populations who engage in ritualized/repeated behaviors, to assess the relationship to self-efficacy and physiologically-mediated changes in stress. Subjects will keep a daily timed diary of their behaviors, which will be used to chart stressful events leading to ritualized/repeated behaviors, concomitant changes in subjects' feelings of anxiety, control, confidence, comfort, and security, before, during and after subjects engage in these behaviors. An Oxford Ambulatory Recorder will monitor the physiological changes in heart rate, muscle tension, skin resistance, motion, and breathing, over time and subject- activated events. In-depth structured interviews will explore developmental history, including life stressors leading to and maintaining ritualized behaviors. To comply with traditional clinical assessments of OCD, subjects will complete the Obsessive-Compulsive Check List and be given the Yale-Brown Obsessive-Compulsive Scale (Y-BOCS). This exploratory study is expected to result in an alternative paradigm for understanding the etiology and course of OCD, and result in an alternative approach to therapy, dependent upon eliminating conditions causing a person t feel loss of control and self-efficacy, rather than the traditional therapeutic approach dependent upon eliminating behaviors, through the use of serotonin uptake inhibitor drugs, or behavioral therapy. Students will assist in all levels of research, including collection of data from both phenomenological and physiological measures of stress, codification of structured interviews, analysis of data, and write-up.